A. S. Eakle — Erionite, a new Zeolite. 67 



the loss was 7*68 per cent ; at 200° C. it amounted to 13*32 

 per cent ; at 280° C. it was 15*25 per cent, of which last all 

 but 2 per cent was regained over night, when placed under a 

 beaker in the laboratory. The loss was practically constant for 

 the different temperatures, as shown by repeated trials and dif- 

 ferent durations of heating. All water of crystallization was 

 apparently expelled at 280° C, for on further heating up to 

 400° C. no more loss was experienced. The remaining water 

 was expelled at low red heat, without fusion, the total loss 

 averaging 17*30 per cent. This makes a difference of about 2 

 per cent as probably constitutional water. Alkaline water was 

 still given off at *200° C, but at 280° C. all evidence of 

 ammonia had disappeared. The water of crystallization evi- 

 dently contains the organic substance, and considering the ease 

 with which the fibers absorb moisture, it is readily conceivable 

 that such moisture may have carried a certain amount of 

 organic impurity into the mineral. The amount of ammonia 

 was determined by combustion with soda-lime, collecting the 

 gas in standardized H 2 S0 4 and titrating with IvOH solution, 

 the result being 0*22 per cent. While this amount is too 

 small to affect the general formula of the silicate, even if con- 

 sidered an essential constituent, it is nevertheless sufficient to 

 form an important pyrognostic characteristic. The fibers are 

 soluble with extreme difficulty in HC1. Complete decomposi- 

 tion was effected by boiling them in concentrated acid, evapo- 

 rating the solution to dryness, grinding the residue and again 

 boiling, the silica in the end separating as a fine sand, with no 

 gelatinization. In the analyses, decomposition was effected (1) 

 by fusing the fibers with the mixed carbonates, (2) by first 

 igniting to a glass and then fusing with the carbonates, and (3) 

 by dissolving in HC1. These various analyses were sufficient 

 to establish the molecular ratio of the mineral, although from 

 the nature of the material, closely agreeing duplicates were 

 difficult to obtain. An average of the analyses gave 



Calculated for 

 Ratio. 6Si0 2 . Al-jOslCaiKaNa^O + 6H 2 



SiO„ 57*16 = -953 6*03 56-52 



ALO„ ... 16*08 = *158 1* 16*01 



4-40 



CaO 3*50 = -062"] 



MgO 0-66 = *0l 7 ! 



K 3 3*51 = *039 f 3*69 



Na a O -.- 2*47 = *040 J 2'43 



HO 17*30 = *960 6*07 16*95 



Total.. 100*68 100*00 



Here the ratio Si : Al 2 = 6 : 1, Si : H 2 = 1 : 1, R : Al 2 = 1:1, 



